The present invention relates to motor vehicle suspension systems and, more particularly, to a pivot construction for such systems. In accordance with the presently preferred embodiment of this disclosure, the pivot construction connects the end of a leaf spring with a vehicle frame bracket.
The pivot construction includes a pair of ball and socket joints with each joint comprising a ball stud having a shank portion and a head portion. The head portion of each joint is enclosed by a cup-shape polyethylene bearing which, in turn, is nestled within a socket part. A retaining ring encircles the shank and engages the end of the bearing. The open end of the socket is spun over against the retaining ring and exerts a preload upon the polyethylene bearing. An elastomeric annular seal sealingly engages the exterior of the spun over end of the socket, the retaining ring and the shank portion of the ball stud.
The end of the leaf spring is formed into an eye that receives a sleeve. A generally hat-shape combination thrust washer and seal member is situated at each end of the spring eye. These members have axially extending elastomeric portions that are fitted within the spring eye and engage the ends of the sleeve. The frame bracket has a bifurcated construction with a pair of aligned holes. The socket parts of the two joints are seated in the holes in the frame bracket. The shanks of the ball studs extend through the center thrust washer and seal members and into the sleeve within the spring eye. The ends of the shanks are juxtaposed. The bifurcations of the frame bracket have radially extending slots and a pinch bolt extends through each of the bifurcations to secure the socket parts to the bracket.
A suspension pivot according to this invention is characterized by its durability and its suitability for heavy duty truck applications. The seal at the mouth of the socket retains lubricant within the bearing cups. The combination thrust washer and seal members have portions which engage the spring eye, the shank portions of the ball studs and the ends of the sleeve whereby contaminants are excluded.
The double ball and socket joint construction of this suspension pivot automatically compensates for minor misalignment that may occur between the leaf spring and the frame bracket. Further, the ball and socket construction offers minimum frictional resistance to angular displacement of the spring with respect to the frame bracket. In addition, the seal arrangement assures long bearing life.